1. Field of Invention
This invention relates to a method and apparatus for rolling up a sheet of dough for bread, a piece of confectionery, etc. Particularly, it relates to a method and apparatus for rolling up a piece of a dough sheet, for example, for croissants, and a piece of a dough sheet on which fillings such as sausages, pieces of cheese, pieces of chocolate, creamy materials, jam, etc. are put.
2. Prior Art
There are many prior-art apparatuses for rolling up a sheet of dough. For example, one such prior-art apparatus is provided with a conveyor belt above which a plate or a belt is positioned so that a space is kept between them. When a sheet of dough is passed through the space, it is rolled up.
When a sheet of dough for a croissant is rolled up, its base is put on the conveyor to face in the front direction, and to intersect with the feeding direction of the conveyor, at right angles. Then, the apparatus starts rolling up the sheet from the base side. However, the sheet may not be completely rolled up due to its characteristics. As a result, the sheet may be loosely rolled up. It may not be rolled up at all, but may be deformed when it passes through the roll-up roller. Also, it may be unevenly rolled up across its entire width. Thus, a device has been made to prevent such a dough sheet from being loosely rolled up (see Japanese Patent Laid-open No. 61-271930 and No. 63-22132). Also, another device has been made to prevent just a part of a sheet from being loosely rolled up (see Japanese Patent Laid-open No. 62-61533).
As stated above, some devices are used in prior-art apparatuses. However, they do not make a tight core of a roll when they start rolling up a sheet of dough. Thus, they cannot firmly roll up the sheet of dough, so that they still do not overcome the disadvantages in the prior-art apparatuses.
Also, no apparatus has been made to roll up a sheet of dough on which solid pieces are put.
Also, in prior-art apparatuses some elements have to be adjusted or replaced by other elements, according to the thickness of a sheet of dough and/or the diameter of a roll, so that the apparatuses are expensive.